Helleborus plant named ‘EPB 20’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘EPB 20’, characterized by its upright and mounding plant habit; uniform, continuous and freely flowering habit; relatively large greenish white-colored flowers that are held above the foliar plane on relatively long peduncles; and good garden performance.

Botanical designation: Helleborus×hybridus.

Cultivar denomination: ‘EPB 20’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Helleborus plant, botanically known as Helleborus×hybridus and hereinafter referred to by the name ‘EPB 20’.

The new Helleborus plant is a product of a planned breeding program conducted by the Inventors in Devon, United Kingdom. The objective of the breeding program was to create new freely-flowering Helleborus plants with strong peduncles that hold numerous attractive flowers above the foliar plane.

The new Helleborus plant originated from a cross-pollination conducted by the Inventors in Devon, United Kingdom on Feb. 10, 2007 of a proprietary seedling selection of Helleborus×hybridus identified as code designation 1052XT, as the female, or seed, parent, not patented, with a proprietary seedling selection of Helleborus×hybridus identified as code designation 4861-LVP, as the male, or pollen, parent, not patented. The new Helleborus plant was discovered and selected by the Inventors as a single flowering plant from within the progeny of the stated cross-pollination grown in a controlled greenhouse environment in Devon, United Kingdom on Mar. 14, 2009.

Asexual reproduction of the new Helleborus plant by tissue culture in a controlled greenhouse environment in De Lier, The Netherlands since Oct. 10, 2012, has shown that the unique features of this new Helleborus plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype of the new Helleborus plant may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype of the new Helleborus plant.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘EPB 20’. These characteristics in combination distinguish ‘EPB 20’ as a new and distinct Helleborus plant:

-   -   1. Upright and mounding plant habit.     -   2. Uniform, continuous and freely flowering habit.     -   3. Relatively large greenish white-colored flowers that are held         above the foliar plane on relatively long peduncles.     -   4. Good garden performance.

Plants of the new Helleborus differ from plants of the female parent selection in the following characteristics:

-   -   1. Plants of the new Helleborus are shorter than plants of the         female parent selection.     -   2. Plants of the new Helleborus and the female parent selection         differ in flower color as plants of the female parent selection         have white-colored flowers.

Plants of the new Helleborus differ from plants of the male parent selection in the following characteristics:

-   -   1. Plants of the new Helleborus are shorter than plants of the         male parent selection.     -   2. Plants of the new Helleborus and the male parent selection         differ in flower color as plants of the male parent selection         have light purple-colored flowers.

Plants of the new Helleborus can be compared to plants of Helleborus×hybridus ‘EPBRD01’, disclosed in U.S. Plant Pat. No. 25,685. In side-by-side comparisons conducted in Devon, United Kingdom, plants of the new Helleborus differed from plants of ‘EPBRD01’ in the following characteristics:

-   -   1. Plants of the new Helleborus had longer leaves than plants of         ‘EPBRD01’.     -   2. Plants of the new Helleborus had larger inflorescences and         were more freely flowering than plants of ‘EPBRD01’.     -   3. Plants of the new Helleborus and ‘EPBRD01’ differed in flower         bud color as plants of ‘EPBRD01’ had greenish white-colored         flower buds.     -   4. Plants of the new Helleborus and ‘EPBRD01’ differed slightly         in flower color as plants of ‘EPBRD01’ had light greenish         white-colored flowers.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearance of the new Helleborus plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Helleborus plant.

The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘EPB 20’ grown in a container.

The photograph on the second sheet is a close-up view of a typical flower bud and flowers of ‘EPB 20’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurements and values describe plants grown during the winter in three-liter containers in an outdoor nursery in Boijl, The Netherlands and under cultural practices typical of commercial Helleborus production. During the production of the plants, day temperatures ranged from 0° C. to 10° C. and night temperatures ranged from −15° C. to 0° C. Plants were one year old when the photographs and the description were taken. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2001 Edition, except where general terms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus hybridus ‘EPB 20’. -   Parentage:     -   -   Female, or seed, parent.—Proprietary seedling selection of             Helleborus×hybridus identified as code designation 1052XT,             not patented.         -   Male, or pollen, parent.—Proprietary seedling selection of             Helleborus×hybridus identified as code designation 4861-LVP,             not patented. -   Propagation:     -   -   Type.—By tissue culture.         -   Time to initiate roots, summer.—About 15 days at             temperatures about 22° C. to 25° C.         -   Time to produce a rooted young plant, summer.—About two             months at temperatures about 20° C.         -   Root description.—Fleshy, vigorous; typically white to brown             in color, actual color of the roots is dependent on             substrate composition, water quality, fertilizer type and             formulation, substrate temperature and physiological age of             roots. -   Plant description:     -   -   Plant and growth habit.—Herbaceous perennial; upright and             mounding plant habit with flowers held above the foliar             plane; moderately vigorous to vigorous growth habit.         -   Plant height.—About 25 cm to 35 cm.         -   Plant diameter (area of spread).—About 20 cm to 25 cm.         -   Stems.—Strength: Strong. Aspect: Mostly upright. Texture:             Smooth, glabrous. Luster: Shiny. Color: Close to 146C with             spots, close to 187A. -   Leaf description:     -   -   Arrangement.—Leaves arranged alternately in a basal rosette;             leaves palmately compound with three to five leaflets per             leaf.         -   Leaflet length.—About 12 cm to 15 cm.         -   Leaflet width.—About 8 cm to 10 cm.         -   Leaflet shape.—Ovate.         -   Leaflet apex.—Acute.         -   Leaflet base.—Acute.         -   Leaflet margin.—Serrate.         -   Leaflet texture, upper and lower surfaces.—Smooth, glabrous;             leathery.         -   Leaflet luster, upper surface.—Shiny.         -   Leaflet luster, lower surface.—Somewhat shiny.         -   Leaflet venation pattern.—Pinnate.         -   Leaflet color.—Developing leaves, upper surface: Close to             137A; center, close to 193A. Developing leaves, lower             surface: Close to 138B. Fully expanded leaves, upper             surface: Close to 139A; venation, close to 139D, proximally,             close to 187A. Fully expanded leaves, lower surface: Close             to 137C; venation, close to 139C, proximally, close to 187A.         -   Petioles.—Length: About 10 cm to 16 cm. Diameter: About 5 mm             to 7 mm. Texture, upper and lower surfaces: Smooth,             glabrous. Color, developing leaves, upper and lower             surfaces: Close to 146C; spots, close to 187A. Color, fully             expanded leaves, upper and lower surfaces: Close to 146C;             spots, close to N199A. -   Flower description:     -   -   Flower shape and habit.—Single rotate flowers arranged in             loosely branched cymes; freely flowering habit with             typically about 15 to 20 flowers developing per cyme and up             to 50 flowers developing per cyme in the second year of             growth; flowers facing outwardly and somewhat drooping.         -   Fragrance.—None detected.         -   Natural flowering season.—Plants begin flowering about two             months after planting; plants flower from January until             March in the United Kingdom.         -   Flower longevity on the plant.—About two to three months;             flowers persistent.         -   Inflorescence height.—About 25 cm to 30 cm.         -   Inflorescence diameter.—About 20 cm to 30 cm.         -   Flower buds.—Length: About 1 cm to 3 cm. Diameter: About 1             cm to 2 cm. Shape: Ovoid. Color: Close to 145C overlain with             close to 186D.         -   Flower diameter.—About 8 cm.         -   Flower depth (height).—About 2 cm to 3 cm.         -   Petals.—None observed; transformed into nectaries.         -   Sepals.—Quantity and arrangement: Five arranged in a single             whorl. Length: About 4 cm. Width: About 3 cm to 4 cm. Shape:             Elliptic to obovate. Apex: Obtuse and occasionally             emarginate. Base: Rounded. Margin: Mostly entire. Texture,             upper and lower surfaces: Smooth, glabrous. Luster, upper             and lower surfaces: Matte. Color: When opening and fully             opened, upper surface: Close to 145D; color does not change             with development. When opening and fully opened, lower             surface: Close to 145D; towards the margins, close to 186D;             color does not change with development.         -   Peduncles.—Length: About 20 cm. Diameter: About 5 mm to             10 mm. Strength: Strong. Aspect: Mostly upright. Texture:             Smooth, glabrous. Color: Close to 146C; spots, close to             187A.         -   Pedicels.—Length: About 4 cm to 10 cm. Diameter: About 3 mm             to 4 mm. Aspect: About 10° from peduncle axis. Strength:             Strong. Texture: Smooth, glabrous. Color: Close to 146C;             spots, close to 187A.         -   Reproductive organs.—Stamens: Quantity per flower: About 60.             Filament length: About 1.5 cm to 1.8 cm. Filament color:             Close to 157D. Anther shape: Elliptic to ovate. Anther             length: About 2 mm. Anther color: Close to 10B. Pollen             amount: Scarce. Pollen color: Close to 10B. Pistils:             Quantity per flower: About five. Pistil length: About             2.5 cm. Stigma shape: Club-shaped. Stigma color: Close to             157C. Style length: About 1.5 cm. Style color: Close to             186D. Ovary color: Close to 142B.         -   Nectaries.—Quantity per flower: About 10 to 15. Length:             About 5 mm to 8 mm. Width: About 3 mm. Shape: Funnelform.             Color: Close to N144C; distally, close to 150B.         -   Seeds and fruits.—Seed and fruit development have not been             observed on plants of the new Helleborus. -   Garden performance: Plants of the new Helleborus have been observed     to have good garden performance and to tolerate rain, wind and     temperatures ranging from about −20° C. to about 35° C. -   Pathogen & pest resistance: Plants of the new Helleborus have not     been observed to be resistant to pathogens and pests common to     Helleborus plants. 

It is claimed:
 1. A new and distinct Helleborus plant named ‘EPB 20’ as illustrated and described. 